Remora - ethernet NVEM cnc board

Thanks.
I have RT-1052 based EC500 board.
I tried to pick settings for X axis and joint 0.
Slowing down did help a little, but I still get random following joint 0 errors.

I don't understand, if I don't need to set base period. (in default config its 0 as well as in yours)
EC500 should be capable of 460kHz stepping rate.
I'm trying to set up JMC servo with 5000 steps per rotation on 5mm pitched screw with max speed of 100mm/s.
That would make an stepping rate of 100kHz.
My current PC latencies are ~80000 for servo thread and ~80000 for base thread while playing some 4k video and 5glxgears.
(intel i5 6500, 16GB Ram, onboard GPU)
Does it even matter, since the stepping should be done on the EC500 board? (is this why base thread is 0 in default ini file?)

also there is some weird behavior: the axis moves with correct velocity. But it never reaches the exact target, only slowly crawls close to it. (See attached video )
Somebody here described similar issue. If I recall correctly, it has to do something with deadband?


 

If you have a look in the .ini file from the previous post, on line 144 at the end of the [AXIS_X] section you will see the pgain value that I put into mine to cure this.

There is a corresponding line required in the .hal file on line 66 in this case. This sets the appropriate remora hal pin.

This worked for me using stepper motors using a 4mm pitch lead screw. You'll have to play with this to see what works for you.

If you are feeding the encoders back into the EC500 you might want to have a look at one of the earlier posts in this thread for the other remora pins that affect the PID tuning & you might have to do some proper PID tuning (which I have never done)

Alex

Actually JMC integrated servos dont have any feedback so its basically open loop mode just like stepper motor. My bad. I did not described this. So, there is no feedback back to EC500

The Remora firmware for the RT1052 NVEM / EC300 / EC500 is still only running a base thread frequency of 40kHz. So you will need to work within the current limitation until this is increased, which you could try by compiling your own version and changing the PRU_BASEFREQ in configuration.h. The RT1052 running at +500Mhz should easily do a faster thread, I just have not got around to testing.

I'll also be revisiting the DMA step generation once I've got a few other things completed.

An Easter gift for EC500 users. I have just pushed a dedicated firmware for the EC500 to the main branch.

github.com/scottalford75/Remora-RT1052/b...t1052-EC500-beta.bin

All of the IO except for the MPG is now available. Inputs are numbered sequentially matching the headers. ie FHA = remora.input.0 through to IN16 = remora.input.19

Similarly the outputs are remora.output.0 to 15

The MPG inputs are a bit of a mystery still as I have not been successful in scanning the IO ports for these. For most people the 16 inputs and outputs should be more than enough.

Happy Easter!

Thanks!!
I have flashed new firmware already. Unfortunately I'm still at early stage with linuxcnc.
The current problem is that I'm struggling with unexpected latency delays:

I'm running LinuxCNC 2.8.4 Debian 10 Buster PREEMPT-RT ISO.
I have EC500 with RT1052 and PC is HP Prodesk 400 G4 with i5 6500 4c/4t and isolcpus=2,3, 16GB Ram and integrated graphics.
I am getting latency under 80k with dozen of glxgears and 4k video in background.

But I think there are some spikes in servo thread, when I toggle machine power (F2) ON in linuxcnc.


What am I doing wrong, or am I missing something?

 

Hi,
first, thanks for remora

Question: how can i invert one dir pin ?
i'm using the ec300 v5

"Board": "NVEM",
"Modules":[
{
"Thread": "Base",
"Type": "Stepgen",
"Comment": "X - Joint 0 step generator",
"Joint Number": 0,
"Step Pin": "PE_15",
"Direction Pin": "PE_14"
},

Thanks,
Olli

meister wrote:

Hi,
first, thanks for remora

Question: how can i invert one dir pin ?
i'm using the ec300 v5

"Board": "NVEM",
"Modules":[
{
"Thread": "Base",
"Type": "Stepgen",
"Comment": "X - Joint 0 step generator",
"Joint Number": 0,
"Step Pin": "PE_15",
"Direction Pin": "PE_14"
},

Thanks,
Olli

There is no ability to invert the direction pin in firmware. If your motors are going the wrong direction then all you need to do is change the sign of the INI joint SCALE parameter, ie from +ve to -ve or visa versa.

zmrdko wrote:

Thanks!!
I have flashed new firmware already. Unfortunately I'm still at early stage with linuxcnc.
The current problem is that I'm struggling with unexpected latency delays:

I'm running LinuxCNC 2.8.4 Debian 10 Buster PREEMPT-RT ISO.
I have EC500 with RT1052 and PC is HP Prodesk 400 G4 with i5 6500 4c/4t and isolcpus=2,3, 16GB Ram and integrated graphics.
I am getting latency under 80k with dozen of glxgears and 4k video in background.

Getting the realtime delay when turning machine power on is "normal" when using Remora. Apparently this is because LinuxCNC is not running a base thread. I have not dug into why the error message appears, but I've just got in the habit of clearing it and carrying on.